Unity Asset Store: What does "popularity" and "top paid/free" really mean?

I just noticed something strange in the asset store. Whenever you browse a particular category, you see the big list of packages in the middle and you can sort that list by different attributes including Popularity, which I always assumed meant “most downloaded”.

You can also see on the right sidebar two lists: Top Paid and Top Free. Now I would assume that “Top” is synonymous with “Most Popular”. So, I would think that the Top Paid and Top Free lists are just price filtered versions of the big list sorted by Popularity. But in reality, there seems to be no correlation at all. They seem to be two different sets of criteria. The “Top” lists also don’t match any of the other sort options like “Rating”.

So what does Popularity really mean? What do the two Top lists represent?

The popularity should just reflect how many ‘stars’ any item has. Voting and assigning stars to downloads is still obscure and difficult, but that should be all there’s to it.